Cooling device and power supply

ABSTRACT

A cooling device including an intake duct achieving fluid communication between a vehicle interior and an inner part of a battery case, a fan unit for supplying the air via the intake duct to the inner part of the battery case, and a control device is used. The fan unit includes a fan and a motor driven by a constant voltage system. The control device includes a current value detecting portion and a judging portion. The current value detecting portion detects a current value of an electric current supplied to the motor. The judging portion compares the detected current value and a preset reference current value and, when the detected current value is lower than the reference current value, judges that there is an anomaly in a volume of the air supplied to the battery case.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a cooling device for cooling a batteryfor running mounted on a vehicle such as a hybrid car, and a powersupply including the same.

2. Description of Related Art

In recent years, hybrid electric vehicles (in the following, referred toas hybrid cars) on which an engine and a motor are mounted as a drivingsource have been commercialized and attracted attention. A hybrid carincludes a secondary battery (a power supply) as a power source forsupplying an electric power to a driving motor. In this secondarybattery, charging or discharging is conducted according to the state ofrunning of the vehicle.

Further, the secondary battery to be mounted on the hybrid car generatesa large amount of heat because it is a combination of many single cells.Also, an electrochemical reaction at the time of charging or dischargingin the secondary battery depends on a temperature. Thus, when thetemperature of the secondary battery exceeds a particular temperature,there arise problems of deteriorating performance of the secondarybattery and a shortened lifetime thereof. Accordingly, as shown in JP2002-120568 A, JP 2001-354039 A and JP 2004-136767 A, the power supplyin the hybrid car conventionally has included a cooling device forcooling the battery.

FIG. 10 is a sectional view showing a configuration of a conventionalpower supply. The power supply shown in FIG. 10 includes a battery pack110 and a cooling device. The cooling device supplies an air to an innerpart of the battery pack 110 and cools the battery pack 110 with thesupplied air.

More specifically, the battery pack 110 has a configuration in which aplurality of unit cells 111 are disposed in a battery case 112. Thebattery case 112 is provided with a supply port 113 for supplying theair to its inner part and an exhaust port 114 for discharging the airafter heat exchange. Furthermore, gaps are provided between the adjacentunit cells 111 and between each unit cell 111 and an inner surface ofthe battery case 112 and serve as a passage for the supplied air.

The cooling device includes an intake duct 101, an exhaust duct 102 anda fan unit 103. The intake duct 101 connects the supply port 113 of thebattery case 112 and an air inlet 109 provided in an interior material108 of the vehicle. Also, at an opening of the intake duct 101 on theside of the air inlet 109, a filter member 107 is disposed forpreventing the entry of foreign objects into the battery pack 110.

The exhaust duct 102 connects the exhaust port 114 of the battery case112 and a suction port 103 a of the fan unit 103. The fan unit 103includes a housing 106, a fan 104 disposed in the housing 106 and amotor 105 for driving the fan 104. The housing 106 is provided with thesuction port 103 a and an exhaust port 103 b.

When the fan 104 is driven by the motor 105, the air in a vehicleinterior is supplied through the intake duct 101 to the inner part ofthe battery case 112, so that the temperature rise in each of the unitcells 111 is suppressed. Further, the air that has been warmed up by theunit cells 111 passes through the exhaust duct 102 and is released fromthe exhaust port 103 b provided in the housing 106 of the fan unit 103to the outside of the vehicle.

Moreover, the cooling device shown in FIG. 10 includes a control device120. The control device 120 includes a judging portion 121, a motordriving portion 122 and a temperature detecting portion 123 and switchesa fan speed of the fan 104 between multiple stages (for example, “LOW”,“MIDDLE” and “HIGH”) according to the temperature of the unit cell 111.The motor 105 is driven by a constant voltage system.

More specifically, the temperature detecting portion 123 detects thetemperature of the unit cell 111 based on a signal from a temperaturesensor 124 attached to the unit cell 111. The judging portion 121 judgeswhether the present fan speed is suitable for the detected temperature.

If not, the judging portion 121 selects a fan speed suitable for thedetected temperature. In this case, the judging portion 121 furtheroutputs a signal (a fan speed indicating signal) to the motor drivingportion 122 so that a voltage corresponding to the selected fan speed isapplied to the motor 105.

The motor driving portion 122 switches the voltage applied to the motor105 between multiple stages according to the indication of the judgingportion 121 so as to adjust the fan speed of the fan 104 in stages.Thus, in the case where the judging portion 121 outputs the fan speedindicating signal, the motor driving portion 122 switches the voltage sothat the fan 104 rotates at the selected fan speed.

In this manner, the control device 120 operates the fan 104 whileswitching the fan speed between multiple stages so that the temperatureof the unit cell 111 does not exceed a preset threshold, and suppressesthe temperature rise of the unit cell 111.

In the above-described conventional power supply illustrated in FIG. 10,the filter member 107 becomes clogged with the passage of operation timeof the fan 104. Accordingly, the volume of the air supplied to the innerpart of the battery case 112 (in the following, referred to as a “supplyair volume”) also decreases gradually with the passage of operation timeof the fan 104. If such a situation is left unaddressed, it becomesimpossible to suppress the temperature rise of the unit cell 111 even byoperating the fan 104. This deteriorates the performance of the unitcell 111 and shortens the lifetime thereof.

Furthermore, there also are some cases where the supply air volumedecreases due to a cause other than the clogging of the filter member107, for example, where a foreign object blocks the air inlet 109 or aforeign object staves in the filter member 107 and intrudes into theintake duct 101. In these cases, the temperature rise cannot besuppressed, which deteriorates the performance of the unit cell 111 andshortens the lifetime thereof, similarly to the case where the filtermember 107 is clogged. Consequently, in the above-described conventionalpower supply illustrated in FIG. 10, it is necessary to monitor theclogging of the filter member 107 and the decrease in the supply airvolume due to foreign objects.

Also, in the field of air conditioning equipment such as a warm-airheater, an air conditioner that senses the filter clogging automaticallyhas been known. For example, JP 2002-147863 A discloses a method forsensing a filter clogging in a warm-air heater based on the amount ofchanges in a control value of a fan motor when the filter is not clogged(a reference control value) and a control value of the fan motoroutputted for maintaining the number of revolutions of the fan to atarget number of revolutions.

However, in the above-described conventional power supply illustrated inFIG. 10, the control device 120 has only the function of detecting thetemperature of the unit cell 111 and no function of sensing a decreasein the supply air volume due to clogging or the like of the filtermember 107. Therefore, it is not until the temperature of the unit cell111 rises that a user realizes the clogging of the filter member 107 orthe presence of a foreign object in the intake duct 101. Also, after thetemperature of the unit cell 111 rises, the performance deterioration ofthe unit cell 111 and the shortening of the lifetime thereof alreadymight be caused.

On the other hand, if a user periodically cleans or replaces the filtermember 107 or carries out an inspection in the air inlet 109 and theintake duct 101, the above-mentioned problems can be avoided. However,it is up to a user to do such a work, and a user conceivably might failto do such a work.

Further, applying the method disclosed in JP 2002-147863 A to theabove-described conventional power supply illustrated in FIG. 10 alsocan be considered. However, in this case, the number of revolutions ofthe fan has to be sensed, leading to an increase in the cost of thepower supply. Moreover, in order to obtain the control value of themotor 105, it is necessary to control the motor 105 by the controlmethod disclosed in JP 2002-147863 A, which also increases the cost ofthe power supply.

It is an object of the present invention to solve the problems describedabove and to provide a cooling device capable of sensing an anomaly in asupply air volume due to clogging of a filter provided in an air supplychannel in a battery mounted on a vehicle or a foreign object, and apower supply including the same.

SUMMARY OF THE INVENTION

In order to achieve the above-mentioned object, a first cooling deviceaccording to the present invention is a cooling device for cooling abattery contained in a battery case and mounted on a vehicle, includingan air supply channel achieving fluid communication between a vehicleinterior or an outside of the vehicle and an inner part of the batterycase, an air supply system for supplying air via the air supply channelto the inner part of the battery case, and a control system. The airsupply system includes a fan and a motor for driving the fan, and themotor is driven by a constant voltage system. The control systemincludes a current value detecting portion and a judging portion. Thecurrent value detecting portion detects a current value of an electriccurrent supplied to the motor, and the judging portion compares thecurrent value detected by the current value detecting portion and apreset reference current value and, when the detected current value islower than the reference current value, judges that there is an anomalyin a volume of the air supplied to the battery case.

In the first cooling device described above, the anomaly in a supply airvolume is judged utilizing the electric current value supplied to themotor. Therefore, the first cooling device can judge the anomaly in thesupply air volume with a simple configuration.

In order to achieve the above-mentioned object, a second cooling deviceaccording to the present invention is a cooling device for cooling abattery contained in a battery case and mounted on a vehicle, includingan air supply channel achieving fluid communication between a vehicleinterior or an outside of the vehicle and an inner part of the batterycase, an air supply system for supplying air via the air supply channelto the inner part of the battery case, a control system, and an airvolume measuring system for measuring a volume of the air supplied tothe inner part of the battery case. The air supply system includes a fanand a motor for driving the fan, and the control system includes a motordriving portion, a memory portion and a judging portion. The motordriving portion switches a voltage applied to the motor between multiplestages according to an indication of the judging portion so as to adjusta fan speed of the fan in stages, the memory portion stores a referenceair volume obtained in advance by measuring the actual volume of the airsupplied to the inner part of the battery case when the fan is driven ateach of the stages of the fan speed, and the judging portion calculatesa difference between the reference air volume corresponding to the fanspeed of the fan at constant time intervals or at all times and the airvolume measured by the air volume measuring system at that time and,when the calculated difference is equal to or larger than a presettolerance value, judges that there is an anomaly in the volume of theair supplied to the battery case.

In the second cooling device described above, the anomaly in the supplyair volume is judged utilizing an actual measured value of the supplyair volume. Therefore, the second cooling device can increase theaccuracy in the anomaly judgment in the supply air volume.

In order to achieve the above-mentioned object, a third cooling deviceaccording to the present invention is a cooling device for cooling abattery contained in a battery case and mounted on a vehicle, includingan air supply channel achieving fluid communication between a vehicleinterior or an outside of the vehicle and an inner part of the batterycase, an air supply system for supplying air via the air supply channelto the inner part of the battery case, a control system, and an airvolume measuring system for measuring a volume of the air supplied tothe inner part of the battery case. The air supply system includes a fanand a motor for driving the fan, and the control system includes a motordriving portion, a memory portion and a judging portion. The motordriving portion switches a voltage applied to the motor between multiplestages according to an indication of the judging portion so as to adjusta fan speed of the fan in stages. The memory portion stores a referenceair volume obtained in advance by measuring the actual volume of the airsupplied to the inner part of the battery case when the fan is driven ateach of the stages of the fan speed, and the judging portion determinesan operation time of the fan, calculates a first accumulated air volumeusing the reference air volume and the operation time of the fan,calculates a second accumulated air volume using the air volume measuredby the air volume measuring system and the operation time of the fan,calculates a difference between the first accumulated air volume and thesecond accumulated air volume and, when the calculated difference isequal to or larger than a preset range, judges that there is an anomalyin the volume of the air supplied to the battery case.

In the third cooling device described above, the anomaly in the supplyair volume is judged by comparing an expected value and an actualmeasured value of the accumulated air volume of the air supplied to thebattery case. Therefore, the third cooling device also can increase theaccuracy in the anomaly judgment in the supply air volume.

In order to achieve the above-mentioned object, a fourth cooling deviceaccording to the present invention is a cooling device for cooling abattery contained in a battery case and mounted on a vehicle, includingan air supply channel achieving fluid communication between a vehicleinterior or an outside of the vehicle and an inner part of the batterycase, an air supply system for supplying air via the air supply channelto the inner part of the battery case, a filter member, and a controlsystem. The filter member is disposed so that only the air that haspassed through the filter member is supplied to the inner part of thebattery case. The air supply system includes a fan and a motor fordriving the fan, and the control system includes a motor drivingportion, a memory portion and a judging portion. The motor drivingportion switches a voltage applied to the motor between multiple stagesaccording to an indication of the judging portion so as to adjust a fanspeed of the fan in stages. The memory portion stores a reference airvolume obtained in advance by measuring the actual volume of the airsupplied to the inner part of the battery case when the fan is driven ateach of the stages of the fan speed, and the judging portion determinesan operation time of the fan, calculates an accumulated air volume usingthe reference air volume and the operation time of the fan and, when thecalculated accumulated air volume is equal to or larger than a presetreference accumulated air volume, judges that there is an anomaly in thevolume of the air supplied to the battery case.

In the fourth cooling device described above, the anomaly in the supplyair volume is judged by comparing the accumulated air volume calculatedfrom the fan speed and the operation time and the reference accumulatedair volume serving as an indicator of when to replace or clean thefilter member. Therefore, the fourth cooling device can increase thereliability of avoiding the temperature rise of the battery.

In order to achieve the above-mentioned object, a first power supplyaccording to the present invention includes a battery mounted on avehicle, and a cooling device for cooling the battery. The batteryincludes a plurality of unit cells and a battery case containing theplurality of unit cells. The cooling device includes an air supplychannel achieving fluid communication between a vehicle interior or anoutside of the vehicle and an inner part of the battery case, an airsupply system for supplying air via the air supply channel to the innerpart of the battery case, and a control system. The air supply systemincludes a fan and a motor for driving the fan, and the motor is drivenby a constant voltage system. The control system includes a currentvalue detecting portion and a judging portion, the current valuedetecting portion detects a current value of an electric currentsupplied to the motor, and the judging portion compares the currentvalue detected by the current value detecting portion and a presetreference current value and, when the detected current value is lowerthan the reference current value, judges that there is an anomaly in avolume of the air supplied to the battery case.

In order to achieve the above-mentioned object, a second power supplyaccording to the present invention includes a battery mounted on avehicle, and a cooling device for cooling the battery. The batteryincludes a plurality of unit cells and a battery case containing theplurality of unit cells. The cooling device includes an air supplychannel achieving fluid communication between a vehicle interior or anoutside of the vehicle and an inner part of the battery case, an airsupply system for supplying air via the air supply channel to the innerpart of the battery case, a control system, and an air volume measuringsystem for measuring a volume of the air supplied to the inner part ofthe battery case. The air supply system includes a fan and a motor fordriving the fan, and the control system includes a motor drivingportion, a memory portion and a judging portion. The motor drivingportion switches a voltage applied to the motor between multiple stagesaccording to an indication of the judging portion so as to adjust a fanspeed of the fan in stages. The memory portion stores a reference airvolume obtained in advance by measuring the actual volume of the airsupplied to the inner part of the battery case when the fan is driven ateach of the stages of the fan speed, and the judging portion calculatesa difference between the reference air volume corresponding to the fanspeed of the fan at constant time intervals or at all times and the airvolume measured by the air volume measuring system at that time and,when the calculated difference is equal to or larger than a presettolerance value, judges that there is an anomaly in the volume of theair supplied to the battery case.

Further, in order to achieve the above-mentioned object, a third powersupply according to the present invention includes a battery mounted ona vehicle, and a cooling device for cooling the battery. The batteryincludes a plurality of unit cells and a battery case containing theplurality of unit cells. The cooling device includes an air supplychannel achieving fluid communication between a vehicle interior or anoutside of the vehicle and an inner part of the battery case, an airsupply system for supplying air via the air supply channel to the innerpart of the battery case, a control system, and an air volume measuringsystem for measuring a volume of the air supplied to the inner part ofthe battery case. The air supply system includes a fan and a motor fordriving the fan, and the control system includes a motor drivingportion, a memory portion and a judging portion. The motor drivingportion switches a voltage applied to the motor between multiple stagesaccording to an indication of the judging portion so as to adjust a fanspeed of the fan in stages. The memory portion stores a reference airvolume obtained in advance by measuring the actual volume of the airsupplied to the inner part of the battery case when the fan is driven ateach of the stages of the fan speed, and the judging portion determinesan operation time of the fan, calculates a first accumulated air volumeusing the reference air volume and the operation time of the fan,calculates a second accumulated air volume using the air volume measuredby the air volume measuring system and the operation time of the fan,calculates a difference between the first accumulated air volume and thesecond accumulated air volume and, when the calculated difference isequal to or larger than a preset range, judges that there is an anomalyin the volume of the air supplied to the battery case.

Also, in order to achieve the above-mentioned object, a fourth powersupply according to the present invention includes a battery mounted ona vehicle, and a cooling device for cooling the battery. The batteryincludes a plurality of unit cells and a battery case containing theplurality of unit cells. The cooling device includes an air supplychannel achieving fluid communication between a vehicle interior or anoutside of the vehicle and an inner part of the battery case, an airsupply system for supplying air via the air supply channel to the innerpart of the battery case, a filter member, and a control system. Thefilter member is disposed so that only the air that has passed throughthe filter member is supplied to the inner part of the battery case. Theair supply system includes a fan and a motor for driving the fan, andthe control system includes a motor driving portion, a memory portionand a judging portion. The motor driving portion switches a voltageapplied to the motor between multiple stages according to an indicationof the judging portion so as to adjust a fan speed of the fan in stages.The memory portion stores a reference air volume obtained in advance bymeasuring the actual volume of the air supplied to the inner part of thebattery case when the fan is driven at each of the stages of the fanspeed, and the judging portion determines an operation time of the fan,calculates an accumulated air volume using the reference air volume andthe operation time of the fan and, when the calculated accumulated airvolume is equal to or larger than a preset reference accumulated airvolume, judges that there is an anomaly in the volume of the airsupplied to the battery case.

As described above, the cooling device and the power supply according tothe present invention can sense the anomaly in the volume of the coolingair supplied to the battery (the supply air volume). Thus, a userrealizes the clogging of the filter member and the presence of foreignobjects before the temperature of the battery rises. Consequently, itbecomes possible to avoid the performance deterioration of the batteryand the lifetime shortening thereof, which are caused by the temperaturerise. Also, with the cooling device and the power supply according tothe present invention, the anomaly in the supply air volume can besensed at low cost.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing a schematic configuration of acooling device and a power supply in Embodiment 1 of the presentinvention.

FIG. 2 shows how an electric current supplied to a motor varies in thecase where an anomaly occurs in a supply air volume.

FIG. 3 is a flowchart showing an operation of a control deviceconstituting the cooling device in Embodiment 1 of the presentinvention.

FIG. 4 is a sectional view showing a schematic configuration of acooling device and a power supply in Embodiment 2 of the presentinvention.

FIG. 5 is a flowchart showing an operation of a control deviceconstituting the cooling device in Embodiment 2 of the presentinvention.

FIG. 6 illustrates an example of how a fan is operated.

FIG. 7 is a flowchart showing an operation of a control deviceconstituting a cooling device in Embodiment 3 of the present invention.

FIG. 8 is a sectional view showing a schematic configuration of acooling device and a power supply in Embodiment 4 of the presentinvention.

FIG. 9 is a flowchart showing an operation of a control deviceconstituting the cooling device in Embodiment 4 of the presentinvention.

FIG. 10 is a sectional view showing a configuration of a conventionalpower supply.

DETAILED DESCRIPTION OF THE INVENTION

A first cooling device according to the present invention is a coolingdevice for cooling a battery contained in a battery case and mounted ona vehicle, including an air supply channel achieving fluid communicationbetween a vehicle interior or an outside of the vehicle and an innerpart of the battery case, an air supply system for supplying air via theair supply channel to the inner part of the battery case, and a controlsystem. The air supply system includes a fan and a motor for driving thefan, and the motor is driven by a constant voltage system. The controlsystem includes a current value detecting portion and a judging portion.The current value detecting portion detects a current value of anelectric current supplied to the motor, and the judging portion comparesthe current value detected by the current value detecting portion and apreset reference current value and, when the detected current value islower than the reference current value, judges that there is an anomalyin a volume of the air supplied to the battery case.

In the above-described first cooling device according to the presentinvention, it is preferable that a filter member further is provided.The filter member is disposed so that only the air that has passedthrough the filter member is supplied to the inner part of the batterycase, and the reference current value is set based on the current valueof the electric current supplied to the motor when the fan is drivenwhile an unused filter member is provided.

Also, a second cooling device according to the present invention is acooling device for cooling a battery contained in a battery case andmounted on a vehicle, including an air supply channel achieving fluidcommunication between a vehicle interior or an outside of the vehicleand an inner part of the battery case, an air supply system forsupplying air via the air supply channel to the inner part of thebattery case, a control system, and an air volume measuring system formeasuring a volume of the air supplied to the inner part of the batterycase. The air supply system includes a fan and a motor for driving thefan, and the control system includes a motor driving portion, a memoryportion and a judging portion. The motor driving portion switches avoltage applied to the motor between multiple stages according to anindication of the judging portion so as to adjust a fan speed of the fanin stages. The memory portion stores a reference air volume obtained inadvance by measuring the actual volume of the air supplied to the innerpart of the battery case when the fan is driven at each of the stages ofthe fan speed, and the judging portion calculates a difference betweenthe reference air volume corresponding to the fan speed of the fan atconstant time intervals or at all times and the air volume measured bythe air volume measuring system at that time and, when the calculateddifference is equal to or larger than a preset tolerance value, judgesthat there is an anomaly in the volume of the air supplied to thebattery case.

Further, a third cooling device according to the present invention is acooling device for cooling a battery contained in a battery case andmounted on a vehicle, including an air supply channel achieving fluidcommunication between a vehicle interior or an outside of the vehicleand an inner part of the battery case, an air supply system forsupplying air via the air supply channel to the inner part of thebattery case, a control system, and an air volume measuring system formeasuring a volume of the air supplied to the inner part of the batterycase. The air supply system includes a fan and a motor for driving thefan, and the control system includes a motor driving portion, a memoryportion and a judging portion. The motor driving portion switches avoltage applied to the motor between multiple stages according to anindication of the judging portion so as to adjust a fan speed of the fanin stages. The memory portion stores a reference air volume obtained inadvance by measuring the actual volume of the air supplied to the innerpart of the battery case when the fan is driven at each of the stages ofthe fan speed, and the judging portion determines an operation time ofthe fan, calculates a first accumulated air volume using the referenceair volume and the operation time of the fan, calculates a secondaccumulated air volume using the air volume measured by the air volumemeasuring system and the operation time of the fan, calculates adifference between the first accumulated air volume and the secondaccumulated air volume and, when the calculated difference is equal toor larger than a preset range, judges that there is an anomaly in thevolume of the air supplied to the battery case.

In the above-described second and third cooling devices according to thepresent invention, it is preferable that a filter member further isprovided, and the filter member is disposed so that only the air thathas passed through the filter member is supplied to the inner part ofthe battery case.

Moreover, in the above-described third cooling device according thepresent invention, it is preferable that when the fan is driven atdifferent fan speeds, the operation time of the fan is determined foreach of the different fan speeds, and the first accumulated air volumeis calculated by the judging portion by calculating an accumulated airvolume for each of the different fan speeds from the determinedoperation time of the fan for each of the different fan speeds and thereference air volume corresponding to this fan speed and adding togetherthe calculated accumulated air volumes for the different fan speeds.

A fourth cooling device according to the present invention is a coolingdevice for cooling a battery contained in a battery case and mounted ona vehicle, including an air supply channel achieving fluid communicationbetween a vehicle interior or an outside of the vehicle and an innerpart of the battery case, an air supply system for supplying air via theair supply channel to the inner part of the battery case, a filtermember, and a control system. The filter member is disposed so that onlythe air that has passed through the filter member is supplied to theinner part of the battery case, the air supply system includes a fan anda motor for driving the fan, and the control system includes a motordriving portion, a memory portion and a judging portion. The motordriving portion switches a voltage applied to the motor between multiplestages according to an indication of the judging portion so as to adjusta fan speed of the fan in stages. The memory portion stores a referenceair volume obtained in advance by measuring the actual volume of the airsupplied to the inner part of the battery case when the fan is driven ateach of the stages of the fan speed, and the judging portion determinesan operation time of the fan, calculates an accumulated air volume usingthe reference air volume and the operation time of the fan and, when thecalculated accumulated air volume is equal to or larger than a presetreference accumulated air volume, judges that there is an anomaly in thevolume of the air supplied to the battery case.

Moreover, in the above-described fourth cooling device according thepresent invention, it is preferable that when the fan is driven atdifferent fan speeds, the accumulated air volume is calculated by thejudging portion by determining the operation time of the fan for each ofthe different fan speeds, calculating an accumulated air volume for eachof the different fan speeds from the determined operation time of thefan for each of the different fan speeds and the reference air volumecorresponding to this fan speed and adding together the calculatedaccumulated air volumes for the different fan speeds. It is furtherpreferable that the reference accumulated air volume is set to anaccumulated air volume from a time when the filter member in an unusedstate is disposed and the fan starts to be driven at a constant fanspeed until an actual measured value of the volume of the air suppliedto the inner part of the battery case becomes 80% or smaller of thevolume of the air at the time when the fan starts to be driven.

Additionally, a power supply according to the present invention ischaracterized by having a battery mounted on a vehicle and any of theabove-described first to fourth cooling devices according to the presentinvention.

Embodiment 1

The following is a description of a cooling device and a power supply inEmbodiment 1 of the present invention, with reference to FIGS. 1 to 3.FIG. 1 is a sectional view showing a schematic configuration of thecooling device and the power supply in Embodiment 1 of the presentinvention.

As shown in FIG. 1, the power supply includes a battery pack 10 to bemounted on a vehicle such as a hybrid car, and a cooling device. Thecooling device supplies a cooling air into the battery pack 10 similarlyto the conventional cooling device illustrated in FIG. 10. In Embodiment1, as shown in FIG. 1, the battery pack 10 includes a plurality of unitcells 11 and a battery case 12. Each of the unit cells 11 is a nickelmetal-hydride storage battery or a lithium ion storage battery. Also, aplurality of the unit cells 11 are received in the battery case 12. Itshould be noted that, in the present invention, the unit cell 11 may bea cell or constituted by a plurality of cells.

The battery case 12 is provided with a supply port 13 for supplying thecooling air to its inner part and an exhaust port 14 for discharging theair after heat exchange. Furthermore, gaps are provided between theadjacent unit cells 11 and between each unit cell 11 and an innersurface of the battery case 12 and serve for passage of the suppliedair.

The cooling device includes an intake duct 1, an exhaust duct 2, a fanunit 3 and a control device 20. The intake duct 1 achieves fluidcommunication between an inside of the vehicle and the inner part of thebattery case 12 and functions as an air supply channel for supplying theair inside of the vehicle to the battery case. In Embodiment 1, theintake duct 1 connects the supply port 13 of the battery case 12 and anair inlet 9 provided in an interior material 8 of the vehicle.

Also, in Embodiment 1, at an opening of the intake duct 1 on the side ofthe air inlet 9, a filter member 7 is disposed for preventing the entryof foreign objects into the battery pack 10. The filter member 7 isdisposed so that only the air that has passed through the filter member7 is supplied to the inner part of the battery case 12.

The exhaust duct 2 functions as an air exhaust channel for exhaustingthe air from the battery case 12. In Embodiment 1, the exhaust duct 2connects the exhaust port 14 of the battery case 12 and a suction port 3a of the fan unit 3. The air after heat exchange is sent via the exhaustduct 2 to the fan unit 3 and discharged through an exhaust port 3 b ofthe fan unit 3 to the outside of the vehicle.

The fan unit 3 functions as an air supply system for supplying the airvia the intake duct 1 to the inner part of the battery case 12. Also,the fan unit 3 includes, a fan 4, a motor 5 for driving the fan 4 and ahousing 6 receiving the fan 4. The suction port 3 a and the exhaust port3 b of the fan unit 3 are provided in the housing 6.

In Embodiment 1, the suction port 3 a of the fan unit 3 is connected tothe exhaust duct 2 as described above. Therefore, when the fan 4 isdriven by the motor 5, the air inside the battery case 12 is drawn,whereby the air inside the vehicle is supplied to the inner part of thebattery case 12.

The control device 20 includes a judging portion 21, a memory portion22, a current value detecting portion 23, a motor driving portion 24 anda temperature detecting portion 25. Similarly to the temperaturedetecting portion 123 shown in FIG. 10, the temperature detectingportion 25 detects the temperature of the unit cell 11 based on a signalfrom a temperature sensor 27 attached to the unit cell 11. Also, thetemperature detecting portion 25 outputs a signal specifying thedetected temperature to the judging portion 21.

The judging portion 21 judges whether the present fan speed is suitablefor the detected temperature similarly to the judging portion 121 shownin FIG. 10. If not, the judging portion 21 selects a fan speed suitablefor the detected temperature. In this case, the judging portion 21further outputs a signal (a fan speed indicating signal) to the motordriving portion 24 so that a voltage corresponding to the selected fanspeed is applied to the motor 5.

Similarly to the motor driving portion 122 shown in FIG. 10, the motordriving portion 24 switches the voltage applied to the motor 5 betweenmultiple stages according to the indication of the judging portion 21 soas to adjust the fan speed of the fan 4 in stages. In the case where thejudging portion 21 outputs the fan speed indicating signal, the motordriving portion 24 applies the voltage corresponding to the selected fanspeed to the motor 5. In this way, the fan 4 rotates at the selected fanspeed. It should be noted that the motor 5 is driven by a constantvoltage system. Accordingly, as long as the fan speed indicating signalis not inputted to the motor driving portion 24, the present voltage ismaintained, so that a constant voltage is applied to the motor 5.

As described above, similarly to the conventional example illustrated inFIG. 10, the control device 20 switches the voltage applied to the motor5 between multiple stages according to the temperature of the unit cell11 so as to adjust the fan speed of the fan 4 in stages. However, unlikethe conventional example illustrated in FIG. 10, the judging portion 21can judge whether there is an anomaly in the volume of the air suppliedto the inner part of the battery case 12 (the supply air volume) usingthe memory portion 22 and the current value detecting portion 23 inEmbodiment 1.

Here, referring to FIG. 2, the principle of the anomaly judgment in thesupply air volume in Embodiment 1 will be described. FIG. 2 shows how anelectric current supplied to the motor varies in the case where ananomaly occurs in the supply air volume. For example, when the filtermember 7 becomes clogged considerably, a foreign object blocks the airinlet 9 or a foreign object intrudes in the intake duct 1, the load onthe motor 5 decreases. At this time, since the motor 5 is driven on theconstant voltage system as described above, a current value Im of theelectric current supplied to the motor 5 drops as shown in FIG. 2.

Thus, in Embodiment 1, a threshold (a reference current value Ie) ispreset to the electric current supplied to the motor 5, and the judgingportion 21 is made to compare the current value Im and the referencecurrent value Ie, thereby judging whether there is any anomaly in thesupply air volume.

Incidentally, in Embodiment 1, the reference current value Ie is storedin the memory portion 22. Also, the current value Im is detected by thecurrent value detecting portion 23 based on a signal sent from thecurrent sensor 26 to the current value detecting portion 23. The currentvalue detecting portion 23 outputs a signal specifying the detectedcurrent value Im to the judging portion 21 (see FIG. 1).

Referring to FIG. 3, the processing of the anomaly judgment in thesupply air volume in the control device 20 will be described. FIG. 3 isa flowchart showing an operation of the control device constituting thecooling device in Embodiment 1 of the present invention.

As shown in FIG. 3, the judging portion 21 first reads out the referencecurrent value Ie from the memory portion 22 (Step S1). Next, the judgingportion 21 obtains the current value Im based on the signal from thecurrent value detecting portion 23 (Step S2). Further, the judgingportion 21 compares the current value Im and the reference current valueIe (Step S3).

If the current value Im is not judged to be smaller than the referencecurrent value Ie in Step S3, the judging portion 21 executes Step S2again. It should be noted that the re-execution of Step S2 followingStep S3 can be carried out after a certain time period.

On the other hand, if the current value Im is judged to be smaller thanthe reference current value Ie in Step S3, the judging portion 21 judgesthat there is an anomaly in the supply air volume, and outputs a warningsignal to the ECU (electronic control unit) of the vehicle as shown inFIG. 1 (Step S4). When the warning signal is outputted, the ECU of thevehicle warns a driver with a liquid crystal display attached to a meterpanel or the like or a warning lamp in the vehicle, for example.Incidentally, the ECU of the vehicle is omitted from FIG. 1.

As described above, the cooling device and the power supply inEmbodiment 1 monitor an anomaly in the supply air volume based on thecurrent value supplied to the motor. Thus, unlike the conventionalcooling device and power supply, the cooling device and the power supplyin Embodiment 1 can sense a cooling air shortage before the temperatureof the unit cell 11 rises. Consequently, it is possible to avoid thedeterioration in the performance of the unit cell 11 and the shorteningof the lifetime thereof due to temperature rise.

It should be noted that the supply air volume recovers if the foreignobject that has blocked the air inlet 9 is removed, for example, afterthe judging portion 21 outputs the warning signal. Thus, Embodiment 1also may be in a mode allowing the control device 20 to clear thewarning when the supply air volume has recovered. More specifically, acurrent value serving as a warning clearance condition (a warningclearance current value) Ic is set in advance (see FIG. 2) and stored inthe memory portion 22. When the current value Im exceeds the warningclearance current value Ic, the judging portion 21 outputs a signalinstructing the warning clearance to the ECU of the vehicle.

Also, in Embodiment 1, the reference current value Ie is set as follows,for example. First, after an unused filter member 7 is provided, the fan4 is driven by the motor driving portion 24. Next, a current value of anelectric current supplied to the motor at this time is obtained by thecurrent value detecting portion 23. Then, the memory portion 22 stores−10% to +10% of the obtained current value as the reference currentvalue Ie.

Incidentally, driving the fan 4, obtaining the current value and storingthe reference current value Ie described above are conducted for eachfan speed. Also, the reference current value Ie may be set before theshipment of the product or every time the filter member 7 is replaced.Further, based on an indicator separately presented by a manufacturer, auser also may set an arbitrary current value as the reference currentvalue Ie. Moreover, it is preferable that the reference current value Ieis set under a certain environmental condition (for example, under thecondition that the temperature is kept at 25° C.) while spending apreset time period (for example, 24 hours).

Embodiment 2

Now, a cooling device and a power supply in Embodiment 2 of the presentinvention will be described, with reference to FIGS. 4 and 5. FIG. 4 isa sectional view showing a schematic configuration of the cooling deviceand the power supply in Embodiment 2 of the present invention.

As shown in FIG. 4, similarly to Embodiment 1, the power supply inEmbodiment 2 also includes a battery pack 10 and a cooling device forsupplying cooling air into the battery pack 10. Also, the cooling deviceincludes an intake duct 1, an exhaust duct 2, a fan unit 3 and a controldevice 30 similarly to Embodiment 1.

Further, the control device 30 includes a judging portion 31, atemperature detecting portion 35 and a motor driving portion 34similarly to Embodiment 1. With this configuration, the control device30 switches the voltage applied to a motor 5 between multiple stagesaccording to the temperature of a unit cell 11 so as to adjust the fanspeed of a fan 4 in stages.

However, unlike Embodiment 1, an air volume sensor 36 is provided in theexhaust duct 2 in Embodiment 2, as shown in FIG. 4. Further, the controldevice 30 is provided with an air volume measuring portion 33. The airvolume sensor 36 and the air volume measuring portion 33 function as anair volume measuring system for measuring the volume of the air suppliedto a battery case 12.

More specifically, the air volume sensor 36 outputs to the air volumemeasuring portion 33 a signal specifying a flow velocity of the airpassing through the exhaust duct 2. The air volume measuring portion 33calculates an air volume Vr per unit time from the signal from the airvolume sensor 36 and the cross-sectional area of an inner part of theexhaust dust. The air volume Vr corresponds to an actual measured valueof the volume of the air supplied to the inner part of the battery case12 (the supply air volume). Also, the air volume measuring portion 33outputs a signal specifying the calculated air volume Vr to the judgingportion 31.

Unlike the memory portion 22 shown in FIG. 1, a memory portion 32 storesreference air volumes V1 to Vn for respective stages of the fan speed.Each of the reference air volumes V1 to Vn is an air volume obtained bymeasuring the actual volume of the air supplied to the inner part of thebattery case 12 when the fan 4 is driven at each fan speed. For example,in the case where three stages of “LOW”, “MIDDLE” and “HIGH” are set asthe fan speeds, the reference air volumes V1 to V3 are measuredactually, and the actual measured values are stored individually.Incidentally, the reference air volumes V1, V2 and V3 respectivelycorrespond to the fan speeds “LOW”, “MIDDLE” and “HIGH”.

In Embodiment 2, the reference air volume is measured actually in thestate where an unused filter member 7 is provided. Further, although theactual measurement of the reference air volume preferably is conductedusing the air volume sensor 36 as described above, it also may beconducted with a separate air volume measuring device placed in theintake duct 1 or the exhaust duct 2. The reference air volumecorresponds to the volume of the air actually supplied to the batterycase 12 when the fan 4 is driven in the state where the filter member 7is not clogged.

Also, in Embodiment 2, the judging portion 31 judges whether there is ananomaly in the supply air volume by comparing the air volume Vr obtainedfrom the air volume sensor 36 and the air volume measuring portion 33when a vehicle is running and a reference air volume Vm corresponding tothe fan speed at this time (1≦m≦n). Here, referring to FIG. 5, aprocessing of the anomaly judgment in the supply air volume in thecontrol device 30 will be described. FIG. 5 is a flowchart showing anoperation of the control device constituting the cooling device inEmbodiment 2 of the present invention.

As shown in FIG. 5, the judging portion 31 first specifies apresently-set fan speed from the latest fan speed indicating signaloutputted to the motor driving portion 34 (Step S11). Next, the judgingportion 31 reads out the reference air volume Vm corresponding to thefan speed specified in Step S11 from the memory portion 32 (Step S12).

Subsequently, the judging portion 31 obtains a present air volume Vrbased on the signal outputted from the air volume measuring portion 33(Step S13). Further, the judging portion 31 calculates the differencebetween the reference air volume Vm and the present air volume Vr andjudges whether the calculated difference is equal to or larger than apreset tolerance value X (Step S14).

If the calculated difference is judged not to be equal to or larger thanX in Step S14, the judging portion 31 judges whether the fan speed hasbeen changed (Step S16). If it has, the judging portion 31 executes StepS11 again. If not, the judging portion 31 executes Step S13 again. Itshould be noted that the re-execution of Step S11 or S13 following StepS16 can be carried out after a certain time period.

On the other hand, if the calculated difference is judged to be equal toor larger than X in Step S14, the judging portion 31 judges that thereis an anomaly in the supply air volume, and outputs a warning signal toECU (not shown) of the vehicle as shown in FIG. 4 (Step S15). When thewarning signal is outputted, the ECU of the vehicle warns a driver witha liquid crystal display attached to a meter panel or the like or awarning lamp in the vehicle, for example.

As described above, the cooling device and the power supply inEmbodiment 2 monitor an anomaly in the supply air volume by measuringthe actual volume of the air supplied to the inner part of the batterycase 12 (the supply air volume). Thus, similarly to Embodiment 1, thecooling device and the power supply in Embodiment 2 also can sense acooling air shortage before the temperature of the unit cell 11 rises.Consequently, it is possible to avoid the deterioration in performanceof the unit cell 11 and the shortening of lifetime thereof due totemperature rise.

The reference value X can be set suitably according to an environment inwhich the vehicle is used. For example, if a limit is placed at the timewhen the present air volume Vr is 90% of the reference air volume Vm, itis appropriate to set X=0.11 Vm. Also, the tolerance value X may be setbefore the shipment of the product or every time the filter member 7 isreplaced. Further, based on an indicator separately presented by amanufacturer, a user may set the tolerance value X arbitrarily.

Although the air volume sensor 36 is provided in the exhaust duct 2 inthe example illustrated in FIG. 4, Embodiment 2 is not limited to this.The air volume sensor 36 also may be provided in the intake duct 1. Inthis case, the volume of the air that is to be supplied to the innerpart of the battery case 12 is measured.

Embodiment 3

Now, a cooling device and a power supply in Embodiment 3 of the presentinvention will be described, with reference to FIGS. 6 and 7. Thecooling device and the power supply in Embodiment 3 have configurationssimilar to those in Embodiment 2 shown in FIG. 4. Also, a memory portionin Embodiment 3 stores reference air volumes V1 to Vn for respectivestages of the fan speed similarly to that in Embodiment 2.

However, Embodiment 3 is different from Embodiment 2 in the processingof the anomaly judgment in the supply air volume conducted by thejudging portion. Also, the judging portion has a function of measuringhow long the fan is operated from an arbitrary point in time. Moreover,in the case where the fan is driven at different fan speeds, the judgingportion measures the operation time of the fan for each fan speed.

FIG. 6 illustrates an example of how the fan is operated. In FIG. 6, thevertical axis indicates the fan speed, whereas the horizontal axisindicates time t. In FIG. 6, the origin of the time t is a point in timeat which the fan starts to be operated after a new filter member isattached. Further, in FIG. 6, a present time of day is expressed by T.

Here, referring to FIG. 7, the processing of the anomaly judgment in thesupply air volume in the control device in the case where the fan isdriven as shown in FIG. 6 will be described. FIG. 7 is a flowchartshowing an operation of the control device constituting the coolingdevice in Embodiment 3 of the present invention. The followingdescription will refer to FIG. 4 used in Embodiment 2 where appropriate.

As shown in FIG. 7, the judging portion first obtains the present airvolume Vr based on a signal outputted from an air volume measuringportion (Step S21). Next, using the obtained air volume Vr, the judgingportion calculates an accumulated air volume Qr until the present time Tby the equation (1) below (Step S22).Qr=∫ ₀ ^(T) Vrdt  (1)

In the case where, prior to the present time T (at a time T′), anaccumulated air volume Q′r from t=0 to t=T′ already is calculated, Qr iscalculated using the equation (2) below.Qr=Q′r+∫ _(T′) ^(T) Vrdt  (2)

Next, the judging portion specifies a presently-set fan speed from thelatest fan speed indicating signal outputted to the motor drivingportion (Step S23). Further, the judging portion reads out the referenceair volume Vm corresponding to the specified fan speed from the memoryportion (Step S24). In the example illustrated in FIG. 6, the referenceair volume V1 is read out.

Subsequently, the judging portion calculates an accumulated air volumeQ′m from the read-out reference air volume Vm and an operation time fromthe time when the present fan speed is set (t=t3) to the time T (StepS25). In the example illustrated in FIG. 6, the reference air volumefrom t=t3 to t=T is V1, and the reference air volume does not varyduring this time. Thus, the accumulated air volume Q′m is calculated inStep S25 by the equation (3) below.Q′m=∫ _(t3) ^(T) V1dt=V1×(T−t3)  (3)

Next, the judging portion calculates a total accumulated air volume Qm(Step S26). More specifically, in the case where the accumulated airvolume when the fan is driven at a different fan speed set before thepresent fan speed is calculated already, this accumulated air volume andthe accumulated air volume Q′m calculated in Step S25 are addedtogether. The accumulated air volume obtained by this addition is usedas the total accumulated air volume Qm.

On the other hand, in the case where only the present fan speed is set,the accumulated air volume Q′m calculated in Step S25 is used as thetotal accumulated air volume Qm. It should be noted that the totalaccumulated air volume Qm calculated as above corresponds to anaccumulated air volume that is expected to be supplied to the batterycase 12 from t=0 to t=T.

In the example illustrated in FIG. 6, by adding the accumulated airvolume Q′m calculated in Step S25 to the accumulated air volume from t=0to t=t3, the total accumulated air volume Qm from t=0 to t=T isobtained. In the example illustrated in FIG. 6, since the reference airvolume at 0≦t≦t1 and t3≦t≦T is V1, that at t1≦t≦t2 is V2 and that att2≦t≦t3 is V3, the total accumulated air volume Qm in Step S26 iscalculated by the equation (4) below.

$\begin{matrix}\begin{matrix}{{Qm} = {{\int_{0}^{{t\; 1} + {({T - {t\; 3}})}}{V\; 1\ {\mathbb{d}t}}} + {\int_{t\; 1}^{t\; 2}{V\; 2\ {\mathbb{d}t}}} + {\int_{t\; 2}^{t\; 3}{V\; 3\ {\mathbb{d}t}}}}} \\{= {{V\; 1 \times ( {{t\; 1} + T - {t\; 3}} )} + {V\; 2 \times ( {{t\; 2} - {t\; 1}} )} + {V\; 3 \times ( {{t\; 3} - {t\; 2}} )}}}\end{matrix} & (4)\end{matrix}$

Subsequently, the judging portion calculates the difference between thetotal accumulated air volume Qm calculated in Step S26 and theaccumulated air volume Qr calculated in Step S22 and judges whether thecalculated difference is equal to or larger than a preset tolerancevalue Y (Step S27).

If the calculated difference is judged not to be equal to or larger thanYin Step S27, the judging portion executes Step S21 again. It should benoted that the re-execution of Step S21 following Step S27 can becarried out after a certain time period.

On the other hand, if the calculated difference is judged to be equal toor larger than Y in Step S27, the judging portion judges that there isan anomaly in the supply air volume, and outputs a warning signal to theECU (not shown) of the vehicle (Step S28). When the warning signal isoutputted, the ECU of the vehicle warns a driver with a liquid crystaldisplay attached to a meter panel or the like or a warning lamp in thevehicle, for example. Incidentally, the reference value Y can be setsuitably according to an environment in which the vehicle is used.

As described above, the cooling device and the power supply inEmbodiment 3 monitor an anomaly in the supply air volume by comparingthe expected value and the actual measured value of the accumulated airvolume of the air supplied to the inner part of the battery case 12.Thus, similarly to Embodiment 1, the cooling device and the power supplyin Embodiment 3 also can sense a cooling air shortage before thetemperature of the unit cell 11 rises. Consequently, it is possible toavoid the deterioration in the performance of the unit cell 11 and theshortening of the lifetime thereof due to temperature rise.

Embodiment 4

Now, a cooling device and a power supply in Embodiment 4 of the presentinvention will be described, with reference to FIGS. 8 and 9. FIG. 8 isa sectional view showing a schematic configuration of the cooling deviceand the power supply in Embodiment 4 of the present invention.

As shown in FIG. 8, similarly to Embodiments 1 to 3, the power supply inEmbodiment 4 also includes a battery pack 10 and a cooling device forsupplying a cooling air into the battery pack 10. Also, the coolingdevice includes an intake duct 1, an exhaust duct 2, a fan unit 3 and acontrol device 40 similarly to Embodiment 1.

The control device 40 includes a judging portion 41, a memory portion42, a motor driving portion 43 and a temperature detecting portion 44similarly to Embodiments 1 to 3. With this configuration, the controldevice 40 switches the voltage applied to a motor 5 between multiplestages according to the temperature of a unit cell 11 so as to adjustthe fan speed of a fan 4 in stages.

Further, similarly to the memory portion illustrated in Embodiments 2and 3, the memory portion 42 stores reference air volumes V1 to Vn forrespective stages of the fan speed. The reference air volume actually ismeasured similarly to Embodiments 2 and 3. Also, the judging portion 41has a function of measuring how long the fan 4 is operated from anarbitrary point in time similarly to the judging portion illustrated inEmbodiment 3. In the case where the fan 4 is driven at different fanspeeds, the judging portion 41 measures the operation time of the fan 4for each fan speed.

However, in Embodiment 4, the memory portion 42 further stores areference accumulated air volume Qx. In addition, the judging portion 41carries out an anomaly judgment in a supply air volume using thereference accumulated air volume Qx, which is a different processingfrom that conducted by the judging portion illustrated in Embodiments 1to 3.

Herein, how to calculate the reference accumulated air volume Qx will beexplained. In Embodiment 4, an unused filter member 7 first is providedin the intake duct 1. Next, the fan 4 is driven at a constant arbitraryfan speed. Further, the volume of the air supplied to the inner part ofa battery case 12 is measured actually from the time when the fan 4starts to be driven. In this case, the air volume can be measured usingan air volume measuring device placed in the intake duct 1 or theexhaust duct 2.

When the fan 4 is operated for at least a certain time period, thefilter member 7 becomes clogged gradually, so that the measured airvolume decreases gradually. Here, a point in time is identified at whichthe present air volume becomes considerably smaller than the air volumeat the driving start time due to the clogging of the filter member 7 andany more decrease in the air volume is expected to raise the temperatureof the unit cell 11. Then, an operation time Tx of the fan 4 from thedriving start time to that point in time is determined. Morespecifically, it is appropriate to identify a point in time at which thepresent air volume becomes 80% or smaller, preferably 70% to 80%, of theair volume at the driving start time.

Next, the determined operation time Tx and an air volume Vx(t) from thedriving start time to the above-noted point in time are substituted intothe equation (5) below. As a result, the reference accumulated airvolume Qx is calculated. The calculated reference accumulated air volumeQx corresponds to an accumulated air volume of the air supplied to thebattery case 12 until the filter member becomes clogged considerably.The reference accumulated air volume Qx serves as an indicator of whento replace or clean the filter member 7. Thus, in the case where a totalaccumulated air volume exceeds the reference accumulated air volume, thetemperature of the battery is likely to rise so much that theperformance of the unit cell 11 is deteriorated and the lifetime thereofis shortened.Qx=∫ ₀ ^(Tx) Vx(t)dt  (5)

Incidentally, the cooling device is mounted on a hybrid car. Therefore,it is preferable that the above-described step of calculating thereference accumulated air volume is carried out in the same environmentas that in the case where the cooling device actually is installed inthe hybrid car. More specifically, the power supply including thecooling device is placed under a constant environmental condition, forexample, in a laboratory where the suspended particles of dust are keptconstant in the range of 0.02 mg/m³ to 0.1 mg/m³, the temperature iskept constant in the range of 20° C. to 30° C. and the humidity is keptconstant in the range of 40% to 60%, and the reference accumulated airvolume is calculated. As the battery pack constituting the power supply,a battery pack used in an actual vehicle or that having an equivalentperformance is used.

Now, referring to FIG. 9, the processing of an anomaly judgment in thesupply air volume in the control device 40 will be described. FIG. 9 isa flowchart showing an operation of the control device constituting thecooling device in Embodiment 4 of the present invention. The followingdescription will refer to FIG. 8 where appropriate.

As shown in FIG. 9, the judging portion 41 first specifies apresently-set fan speed from the latest fan speed indicating signaloutputted to the motor driving portion 43 (Step S31). Next, the judgingportion 41 reads out a reference air volume Vm corresponding to thespecified fan speed from the memory portion 42 (Step S32).

Subsequently, the judging portion 41 calculates an accumulated airvolume Q′m from the read-out reference air volume Vm and an operationtime from the time when the present fan speed is set to the present timeT (Step S33). It should be noted that the accumulated air volume Q′m iscalculated in Step S33 similarly to Step S24 in Embodiment 3.

Next, the judging portion 41 calculates a total accumulated air volumeQm (Step S34). More specifically, in the case where the accumulated airvolume when the fan is driven at a different fan speed set before thepresent fan speed is calculated already, this accumulated air volume andthe accumulated air volume Q′m calculated in Step S33 are addedtogether. The accumulated air volume obtained by this addition is usedas the total accumulated air volume Qm. In the case where only thepresent fan speed is set, the accumulated air volume Q′m calculated inStep S33 is used as the total accumulated air volume Qm. It should benoted that the total accumulated air volume Qm is calculated in Step S34similarly to Step S26 in Embodiment 3.

Then, the judging portion 41 reads out a reference accumulated airvolume Qx from the memory portion 42 (Step S35). Thereafter, the judgingportion 41 compares the total accumulated air volume Qm calculated inStep S34 and the reference accumulated air volume Qx read out in StepS35 and judges whether the total accumulated air volume Qm is equal toor larger than the reference accumulated air volume Qx (Step S36).

If the total accumulated air volume Qm is judged not to be equal to orlarger than the reference accumulated air volume Qx (the totalaccumulated air volume Qm is smaller than the reference accumulated airvolume Qx) in Step S36, the judging portion 41 executes Step S31 again.It should be noted that the re-execution of Step S31 following Step S36can be carried out after a certain time period.

On the other hand, if the total accumulated air volume Qm is judged tobe equal to or larger than the reference accumulated air volume Qx inStep S36, the judging portion 41 judges that there is an anomaly in thesupply air volume, and outputs a warning signal to the ECU (not shown)of the vehicle (Step S37). When the warning signal is outputted, the ECUof the vehicle warns a driver with a liquid crystal display attached toa meter panel or the like or a warning lamp in the vehicle, for example.

As described above, the cooling device and the power supply inEmbodiment 4 monitor an anomaly in the supply air volume based on thereference accumulated air volume Qx serving as the indicator of when toreplace or clean the filter member 7. Thus, similarly to Embodiment 1,the cooling device and the power supply in Embodiment 4 also can sense acooling air shortage before the temperature of the unit cell 11 rises.Consequently, it is possible to avoid the deterioration in theperformance of the unit cell 11 and the shortening of the lifetimethereof due to temperature rise.

Incidentally, in Embodiments 1 to 4 described above, the kind, size,material and performance of the filter member 7 are not particularlylimited. However, if an object to be cooled by the cooling device is thebattery pack 10 mounted on a vehicle such as a hybrid car and the airinlet 9 is provided in the interior material 8 of the vehicle, it ispreferable that the filter member 7 is formed of a polypropylene (PP)resin. Further, in the case where the air inlet 9 is not provided in theinterior material 8 of the vehicle, it also is possible to use thefilter member 7 formed of steel wool.

Although the air inlet 9 is provided in the vehicle interior inEmbodiments 1 to 4, the present invention is not limited to this. Theair inlet 9 also can be provided in a vehicle exterior, for example.Moreover, although the fan unit 3 serving as the air supply system isplaced on the air exhausting side in Embodiments 1 to 4, the presentinvention is not limited to this. The fan unit 3 also can be placed onthe air supply side.

The cooling device and the power supply in the present invention form apart of a vehicle on which a battery for running is mounted, such as ahybrid car, and have an industrial applicability.

The invention may be embodied in other forms without departing from thespirit or essential characteristics thereof. The embodiments disclosedin this application are to be considered in all respects as illustrativeand not limiting. The scope of the invention is indicated by theappended claims rather than by the foregoing description, and allchanges which come within the meaning and range of equivalency of theclaims are intended to be embraced therein.

1. A cooling device for cooling a battery contained in a battery caseand mounted on a vehicle, the cooling device comprising: an air supplychannel achieving fluid communication between a vehicle interior or anoutside of the vehicle and an inner part of the battery case; an airsupply system for supplying a volume of air via the air supply channelto the inner part of the battery case; a filter member disposed in theair supply channel; and a control system, the control system including acurrent value detecting portion and a judgment portion; wherein the airsupply system comprises a fan and a motor for driving the fan, the motorbeing driven by a constant voltage system, the current value detectingportion detects a current value of an electric current supplied to themotor, and the judging portion compares the current value detected bythe current value detecting portion and a preset reference current valueand, when the detected current value of the electric current supplied tothe motor is lower than the preset reference current value, judges thata load on the motor has decreased, wherein the judging portiondetermines from the decreased load on the motor that there is an anomalyin the volume of the air supplied to the battery case, wherein thejudging portion outputs a warning signal when the anomaly is determined,and wherein the reference current value is set based on the currentvalue of the electric current supplied to the motor when the fan isdriven while an unused filter member is provided.
 2. A power supplycomprising: a battery mounted on a vehicle; and a cooling device forcooling the battery; wherein the battery comprises a plurality of unitcells and a battery case containing the plurality of unit cells, thecooling device comprises: an air supply channel achieving fluidcommunication between a vehicle interior or an outside of the vehicleand an inner part of the battery case, an air supply system forsupplying a volume of air via the air supply channel to the inner partof the battery case; a filter member disposed in the air supply channel;and a control system, the air supply system comprises a fan and a motorfor driving the fan, the motor being driven by a constant voltagesystem, the control system comprises a current value detecting portionand a judging portion, the current value detecting portion detects acurrent value of an electric current supplied to the motor, and thejudging portion compares the current value detected by the current valuedetecting portion and a preset reference current value and, when thedetected current value is lower than the preset reference current value,judges that a load on the motor has decreased, wherein the judgingportion determines from the decreased load on the motor that there is ananomaly in the volume of the air supplied to the battery case andoutputs a warning signal, and wherein the reference current value is setbased on the current value of the electric current supplied to the motorwhen the fan is driven while an unused filter member is provided.
 3. Thecooling device of claim 1, wherein the judging portion outputs thewarning signal before a temperature of the battery increases.
 4. Thecooling device of claim 2, wherein the judging portion outputs thewarning signal before a temperature of the battery increases.
 5. Thecooling device of claim 1, wherein the judging portion determinesselects a fan speed of the motor based on a detected temperature of thebattery.